1. Field of the Invention
The present invention pertains to a system for automatically dispensing predetermined quantities of a plurality of liquid products.
2. Description of the Prior Art
It is frequently necessary to selectively dispense a plurality of fluid products into the carrier fluid utilized in various operations and processes. For example, a wide variety of liquid detergents, laundry soaps, iron control agents, neutralizers, etc., are frequently injected into the water utilized in machine clothes washers, dishwashers, etc. This is particularly true for the laundry operation in large commercial institutions (e.g., hotels, restaurants, hospitals, etc.). Since entirely manual dispensing of the various laundry products is uneconomical and unreliable in a commercial environment, numerous attempts have been made to provide either semi-automatic or automatic dispensing of the liquid products.
The presently available semi-automatic dispensing units operate on a load-by-load basis. The amount of each liquid product (or powdered product) necessary to provide the desired cleansing action, neutralizing action, etc., for a single laundry load is measured out and positioned within separate receptacles associated with the laundry machine. In response to an electrical signal generated by the machine, wash water is selectively channeled through one or more of the receptacles at the appropriate time during the machine washing cycle and the product is injected into the washer. The product receptacles are then refilled for the next load. While such semi-automatic apparatus is generally more dependable than entirely manual dispensing, this type of apparatus is still subject to human error in measuring the proper amount of product for each load as well as the proper placement of the products (i.e., placement of each product within the correct receptacle).
The automatic dispensing unit eliminates the necessity of manually measuring the laundry products and manually adding the measured products to the machine at the completion of each washing cycle. However, the presently available apparatus is exceedingly expensive and does not produce as accurate dispensing as is desirable. For instance, one commercially available unit utilizes the conventional formula chart control so as to electrically actuate and deactuate a plurality of pressurized containers containing liquid products and a plurality of product valves to allow selective dispensing of the liquid products. To accomplish this, a hole is cut into the formula chart (i.e., a plastic tape) at an appropriate position and, during the passage of this hole past a pressure sensitive (vacuum) switch, the pressurized tanks are activated to allow dispensing of one or more of the liquid products, However, to dispense the desired amount of each liquid product necessitates extreme accurateness in the cutting of the holes within the formula chart and in the method of controlling and maintaining the desired pressure requirements. The proper control of these variables has proven exceedingly difficult and, consequently, this type of apparatus has not provided as accurate dispensing as is desirable. A further disadvantage of this type of apparatus is the need to transfer the powdered and/or liquid products from their shipping containers into separate high pressure containers for dilution with water and subsequent injection into the laundry machine. Thus, while apparatus is presently available which incorporates the wash cycle and product dispensing system into one system, this apparatus is exceedingly expensive and generally unreliable. Alterntive injection timing apparatus, such as a cam-operated timer, is neither dependable nor readily adjustable.